There is still no announcement of any official installation facility for ReVolt JB I9100 Custom ROM Android 4.2.1 Jellybean for Samsung Galaxy S2 GT I9100 devices. There are however custom ROM’s doing rounds in the market. So long as an official offer is there, why not try them out? Following the steps in this tutorial will help you get it on your device.

Back up all data relevant to you like Contact List, SMS and MMS, Songs and Videos, APN, MMS and GPRS settings, etc. so that they can be restored if lost in the installation process.

Ensure at least 50% charge in phone battery before starting the installation process.

Why Rooting of the device is preferred at the start?

Rooting of the device at start helps in getting rid of any pre-installed stock apps that keep disturbing you and are unwanted. It helps take a back up of Android devices on the SD card for restoration later, when it may be cleaned of things that are making your device slower over long period of usage. Lastly, it helps in overcoming bad stock apps that may be already there, thus improving battery life, performance level, easier user interface and customization. It also helps in achieving faster network speed.

Press and hold Power+Volume Up+Home buttons together to enter the CWM or TWRP recovery mode.

Start with Wipe Data or Factory Reset option. This is done to ensure that the phone does not crash during installation or the ROM is compatible. This would not be required if your ROM is already upgraded to a higher version. For CWM recovery, use the Volume key while if it is TWRP recovery, you can navigate using the touch screen.

Select Wipe Cache Partition from menu and confirm action.

Select Wipe Dalvik Cache again from the menu and confirm action.

From main menu in recovery in SD card, select install zip and confirm the initiation of the installation procedure.

After it is over, return to the menu and reboot the phone. Rebooting may take some time, but your Galaxy S2 GT I9100 will be equipped after that.

Perform Wipe Data or Factory Reset actions. This is done to ensure that the phone does not crash during installation or the ROM is compatible. This would not be required if your ROM is already upgraded to a higher version. For CWM recovery, use the Volume key while if it is TWRP recovery, you can navigate using the touch screen.

Select Wipe Cache Partition from menu and confirm.

Select Wipe Dalvik Cache again from the menu.

From main menu in recovery in SD card, select install zip and confirm the initiation of the installation procedure.

Return to the menu for rebooting. It may take some time, but your device will be equipped after that.

Problem in Rebooting?

In case the device fails to reboot properly, press Power button for 5-10 seconds to initiate rebooting. If the problem still persists, boot into recovery and wipe cache to try rebooting once more.